Mineral induced mechanochemical degradation: The imazaquin case
| Autor: | Uri Mingelgrin, Ahmed Nasser, Zev Gerstl, Nadia Buchanovsky |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Time Factors
Environmental Engineering Birnessite Imazaquin Health Toxicology and Mutagenesis Inorganic chemistry Mass Spectrometry chemistry.chemical_compound X-Ray Diffraction Mechanochemistry Soil Pollutants Environmental Chemistry Chromatography High Pressure Liquid Environmental Restoration and Remediation Chemical decomposition Minerals Herbicides Chemistry Imidazoles Temperature Public Health Environmental and Occupational Health General Medicine General Chemistry Hematite Pollution Grinding Montmorillonite visual_art Quinolines visual_art.visual_art_medium Degradation (geology) Nuclear chemistry |
| Zdroj: | Chemosphere. 75:20-27 |
| ISSN: | 0045-6535 |
| DOI: | 10.1016/j.chemosphere.2008.11.077 |
| Popis: | The potential role of mechanochemical processes in enhancing degradation of imazaquin by soil components is demonstrated. The investigated components include montmorillonite saturated with Na + , Ca 2+ , Cu 2+ and Al 3+ , Agsorb (a commercial clay mix), birnessite and hematite. The mechanical force applied was manual grinding of mixtures of imazaquin and the minerals, using mortar and pestle. The degradation rates of imazaquin in these mixtures were examined as a function of the following parameters: time of grinding, herbicide load (3.9, 8.9, 16.7 and 26.6 mg imazaquin per g mineral), temperature (10, 25, 40 and 70 °C), acidic/basic conditions, and dry or wet grinding. Dry grinding of imazaquin for 5 min with Al-montmorillonite or with hematite resulted in 56% and 71% degradation of the imazaquin, respectively. Wet grinding slightly reduced the degradation rate with hematite and entirely cancelled the enhancing effect of grinding with Al-montmorillonite. Wet grinding in the presence of the transition metals: Ni 2+ , Cu 2+ , Fe 3+ added as chlorides was carried out. Addition of Cu 2+ to Na-montmorillonite loaded with imazaquin was the most effective treatment in degrading imazaquin (more than 90% of the imazaquin degraded after 5 min of grinding). In this treatment, Cu-montmorillonite formation during the grinding process was confirmed by XRD and accordingly, grinding with Cu-montmorillonite gave similar degradation values. LC–MS analysis revealed that the mechanochemical transformation of imazaquin resulted in the formation of a dimer and several breakdown products. The reported results demonstrate once again that mechanochemical procedures offer a remediation avenue applicable to soils polluted with organic contaminants. |
| Databáze: | OpenAIRE |
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